With the development of networks, people increasingly use a network for information transmission, and this also brings a security issue about the information transmission by using the network.
During information transmission on a network, generally a network device integrates transmitted information into a certain file format. After receiving a file sent by using the network by another network device, a computer or a network device generally detects the file. If a type of the file is identifiable and is a secure file type, the network device at a receiving end can subsequently receive and use the file. When it is identified that the type of the file does not belong to a secure file type, processing such as alerting may be performed.
However, when the type of the file transmitted by using the network cannot be identified, a user needs to search the Internet for a tool capable of identifying the file type, and this is quite complicated and has a low success rate. In addition, according to an existing security mechanism, generally a file type that cannot be identified will be processed as an insecure file to protect security of the network device as much as possible. In this way, some secure information cannot be received because the file type cannot be identified.